Down-blast oil-smelting furnace



April 7, 1931. 5 ROGERS I 1,799,643

I DOWN BLAST OIL SMELTING FURNACE Filed Feb. 6, 1 29 2 Sheets-Sheet l IN N April 7, 1931- M. 5. ROGERS 1,799,643

DOWN BLAST OIL SMELTING FURNACE Filed Feb. 6, 1929 2 Sheets-Sheet 2Patented Apr. 7, 1931 i UNITED STATES PATENT OFFICE MATTHEW S. ROGERS,

OF MARTINEZ, CALIFORNIA, ASSIGNOR OF ONE-HALF TO F. E.

KENNEDY, F MARTINEZ, CALIFORNIA DOWN-BLAST OIL-SMELTING FURNACEApplication filed February 6, 1929. Serial No. 338,015.

This invention relates to smelting furnaces and more particularly to avertical down blast and up blast stack system. The application is asubstitution for my abandoned application, Serial No. 666,749, filedOctober 5, 1923.

It is an object of the invention to provide, in combination in asmelting'furnace, a vertical, down blast and up blast system of chimneysin a series, together with asettling chamber or forehearth, and toprovide in the com- 1 bination a secondary or converter hearth in serialrelation, so that the molten metal in the forehearth can be drawn frombelow its burden of slag into the converter chamber and from this drawnseparately.

Another object is to provide, in a vertical, down blast furnace, meansfor relatively increasing the length of time and path of travel of thecharge descending therein and during the course of treatment. In thisconnection, it is an object of the invention to provide a verticalfurnace stack having a substantially continuous, helical recess in itsinner face and to form such recess by an inwardly projecting helix ofsuitable proportions forming a well defined ledge between faces of whichthe helical or circuitous passageway or recess is formed.

It is another object to provide means for the heating of the furnace byoil or gas fuel and to provide means for controlling the feed andadmission of a pulverized mixture of the material to be treated andwhich may consist of raw ores of iron, mercury, copper, lead, and zinc,or which may consist. of iron sands, fluedust, concentrates, mill-dustand other comminuted forms of metalliferous substances. It is an objectto provide for the admission of the temperature-producing fuel as may bedesired in the stack and'in the forehearth and converting chambers andto provide for the admission of air as may be necessary, as well as forthe introduction of carbon, such as soot, into the material to betreated.

A further object is to provide in a" vertical down blast chimney system,means for permitting observation and also to provide explosion doors asmay be necessary.

v Other objects and advantages will be made manifest in the followingspecification of an embodiment of the invention illustrated intheaccompanying drawings, wherein Fig.1 is a vertical section andelevation of one embodiment of the invention.

Fig. 2 is a plan and horizontal section approximately on line 2-2 ofFigure 1.

The apparatus of my present invention by which comminuted material maybe treated according to my present method consists of any suitablenumber of vertical stacks 2, of which only one is here shown, this stackbeing designed and arranged so that descending material therein willfall into the forehearth 3 preferably at one end of the same, and thisforehearth is directly joined in serial fashion with a convertingchamber 4, which in the present case is shown as at the opposite end ofthe forehearth from the end into which the stack 2 discharges.

Preferably, the bottom 3 of the forehearth is inclined so as to permitthe free, gravitational flow of the melt therefrom through an outlet 5into the subjacent converter cham-.

her 4; a suitable transverse wall 6 forms a bridge and end wall for theforehearth 3 and gases from the forehearth chamber may pass through athroat 7 from the forehearth into the converter chamber and thenceupthrough a stack 10.

One of the important features of the present invention is the provisionof means for relatively increasing the time required in the descent ofmaterial discharging from the hopper 8 and through the feed control gate9 down into the stack 2, as compared to a down blast stack having noretarding means. The retarding means of the present invention consistspreferably of a helical, inwardly projecting ledge or shoulder 2*obviously built of the necessary fire-resisting material and forming ahelical or circuitous passageway 2 between faces which arelongitudinally opposite as to the stack.

Air and fuel as may be necessary for the creation of the desiredtemperature are sup plied through nozzle and burner means 12 which, asclearly shown in Figure 2, are arranged tangentially to the circularinterior wall of the. stock2 and the nozzles, of which any suitablenumber and desired arrangement may be provided, are positioned in nozzlepockets 2 in the stack wall, these pockets opening in the bottoms of theturns of the helical passageway 2*. From this it will be seen that asthe comminuted material to be treated, of whatever its character, fallsthrough the regulating and controlling discharge gate 9, the material iscaught up by the swirling blast of flame and gases tangentiallydischarging into the stack 2 and therefore the period of descent ismaterially increased because of the greater length of path through whichthe material must pass in descending through the stack.

Safety or explosion gates 13 are provided at suitable intervals andlocations in the wall of the stack, as also are the usual peep holes 14.The higher end of the forehearth 3 is provided at about the base of thestack with a slag opening 15 and'below this there is shown a slag tap 16through which slag from the forehearth may be drawn as necessary.

To obtain the desired degree of tempera ture and a proper and desiredmixture of gases in the forehearth 3, the sidewalls of this chamber areshown as provided with pockets 3 in which are arranged air blast andburner nozzles 18, these preferably being disposed obliquely andincliningtoward the center and discharge end of the forehearth so as tofacilitate and tend to direct the progressive flow of the gases andbyproducts of combustion toward the converting chamber 4 and toward theup blast stack 10, which is shown in Figure 2 as disposed at one end ofthe converting chamber 4 and is connected thereto by a passageway.

The desired temperature is obtained and controlled in the convertingchamber by air and burner nozzles indicated at 19, these dischargingtoward the gas outlet passageway 4 at the opposite end of theconverter.fur-

nace. 7

The converter furnace is provided with suitable air tuyeres 30, thesepreferably having their discharge ends located below the normal level ofthe chamber.

From the above 1:; will be seen that I have provided a down blastsmelting system in which there is directly combined a forehearth, at thebase of a down draft and reducing stack, and a converter chamber so thatan economy in the utilization of the heated gases from the smeltingfurnace is obtained by passing these gases into the conmelt M in theconverter minuted substances from the top of the stack into thesubjacent forehearth by the provision of the helical baflle and recessor path formed thereby down the inside wall of the chamber.

Further embodiments, modifications and variations may be resorted towithin the principle of the invention.

What is claimed is 1. In a smelting furnace, a stack having meansadjacent its top for feeding a comminuted material into the stack, saidstack having on'its inner surface a helical recess, and burners arrangedat difierent points along the recess discharging in a directiondownwardly along the recess.

2. In a smelting furnace, a down blast smelting stack, the interior ofthe stack gradually-widening from top to bottom, there being asubstantially continuous helical recess formed in the walls of the stackextending from adjacent the top to adjacent the bottom thereof, andburners arranged tangentially of the recess.

In testimony whereof I have signed my name to this specification.

MATTHEW S. ROGERS.

verter chamber and also running the reduced molten metal directly fromthe forehearth into the converter chamber and directl treating it forpurification.

It will also be seen that I have provided an extremelysimple, effectiveand durable means for materially increasing the length of time requiredin the fall of the com-

